ALTITUDE CALCULATION DEVICE AND ALTITUDE CALCULATION PROGRAM

摘要

A portable terminal (1) comprises: a time information acquisition unit (2a) that acquires time information indicating a predetermined time; a positional information acquisition unit (2b) that acquires positional information indicating a predetermined position; a barometric pressure value acquisition unit (2c) that acquires a barometric pressure value at the predetermined position at the predetermined time; a meteorological observation point selection unit (2d) that selects a plurality of meteorological observation points near the predetermined position by using the positional information; a see-level barometric pressure value acquisition unit (2e) that acquires, from a meteorological observation server, see-level barometric pressure values observed at the plurality of meteorological observation points for each predetermined period; a see-level barometric pressure value calculation unit (2f) that calculates a see-level barometric pressure value at the predetermined position by using the see-level barometric pressure values at the plurality of meteorological observation points; a see-level barometric pressure value complementation unit (2g) that complements the see-level barometric pressure value at the predetermined position by the time information; a temperature acquisition unit (2h) that acquires, from the meteorological observation server, temperatures observed at the plurality of meteorological observation points for each predetermined period; a temperature specifying unit (2i) that specifies a temperature at the predetermined position by using the temperatures at the plurality of meteorological observation points; and an altitude calculation unit (2j) that calculates an altitude by using the barometric pressure value at the predetermined position, the complemented see-level barometric pressure value at the predetermined position, and the temperature at the predetermined position.